Analytical solution to solve the point reactor kinetics equations

New analytical solution for solving the point reactor kinetics equations with multi-group of delayed neutrons is presented. This solution is based on the roots of inhour equation, eigenvalues of the coefficient matrix. The inhour equation presents in new sample formula. The analytical solution represents the exact analytical solution for the point kinetics equations of multi-group of delayed neutrons with constant reactivity. Also, it represents the accurate solution for solving the point kinetics equations of multi-group of delayed neutrons with ramp and temperature feedback reactivities. This method are applied to different types of reactivity and compared to the traditional methods.